1. Field of the Invention
The present invention relates to a vibration actuator, a lens barrel, a camera, a manufacturing method for a vibration body and a manufacturing method for a vibration actuator.
2. Description of the Related Art
A vibration actuator causes an electromechanical transducer element to expand and contract based on a driving signal, and using this expansion and contraction, generates a progressive vibrational wave (hereinafter, referred to as a progressive wave) into a driving surface of an elastic body. Then, the vibration actuator generates elliptic motion in the driving surface based on this progressive wave, and gives rise to a driving force by driving a relative displacement member that has been brought into pressure-contact with a crest of a wave of the elliptic motion.
In such vibration actuators, various improvements with respect to enhancement of the driving efficiency and other aspects have been achieved. The prior art (for example, see Japanese Unexamined Patent Application No. S63-220782) discloses an example of providing a partitioning border portion in a piezoelectric element main body, wherein the border portion comprises a notch taking the form of a groove in at least a part of the piezoelectric element in a thickness direction to partition the piezoelectric element for each electrode area.
However, the method disclosed in this prior art has the problem of a large number of manufacturing steps of the piezoelectric element leading to increases in production costs.